To order, simple tell the cashier at the front of the shop you want májiàng miàn or point to a bowl situated in front of one of the many other customers. You'll pay for your noodles (9 rmb on my last visit) and receive your receipt.
Then it's time to stake out a table. As this place is usually packed, seats are generally at a premium. Look for patrons on the verge of leaving and hover over their table. Once they have left, slide onto your seat and grab one of the clothespins on your table. Each of the clothespins will be labeled with the number of your table. Simply clip your receipt to it and hand it to one of the waitresses as they hurry past.
Within minutes you'll be rewarded with a creamy bowl of sesame paste noodles, topped off with a splash of chili oil and chives.